1. Field of the Invention
This invention relates to colored pigment compositions of high refractive index and hue intensity and physical properties, and aims generally to improve the same and provide novel processes for the production thereof.
2. Description of the Prior Art
In the prior art it has been well known to produce the so-called "Laked" or "Extended" pigment colors, usually by precipitation of a water soluble organic dye or pigment color base onto an inert and inherently colorless or white substrate material to either impart useful pigmentary properties to an otherwise unsuitable organic or inorganic color material or to give improved physical properties to an already useful color. Such treatments and combinations thereof included the enclosing or encapsulation of inorganic color material such as the lead chromate yellows with a siliceous envelope or encapsulation, to inhibit or reduce their toxicological properties, and also includes the laking of azo and related organic pigments on such insoluble substrate material as alumina, blanc fixe and similar compositions.
All these earlier methods simply dilute the color portion of the resulting pigment composition and essentially provide a wet or dry dispersion of the color pigment or chromogen containing part, intimately admixed with the inert or extender portion of the composition.
Such "Laked" or "Extended" colors are usually considerably duller and much weaker tinctorially than the original chromogen containing constituent, and furthermore are not infrequently themselves easily disunited into the separate components of said composition. This is especially true concerning the use of mixtures of organic color pigments where two or more are combined together to produce a shade different from either alone.